1. Field Of Invention
The invention relates to indoor and outdoor court surfaces for games and activities, especially where a ball is used. More particularly, the invention relates to tennis court surfaces.
2. Background Information
Current tennis court surfaces generally fall under three categories: grass or lawn type surfaces; compacted clay type surfaces; and hard surfaces. These surfaces are different in appearance and playing characteristics and each have advantages and disadvantages. For example, grass courts are characterized by a very fast surface which enhances the speed of a tennis game. However, these court surfaces are expensive to install and maintain and are subject to erratic ball behavior. In addition, the use of grass surfaces is very seasonal.
Clay courts are characterized by a soft, spin receptive surface which induces slow play and helps reduce player injuries. However, clay courts require high maintenance and are also limited to seasonal use because of weather conditions.
Hard courts generally contain asphaltic or concrete pad surfaces painted over with a resinous material usually in the form of an acrylic latex water based emulsion. These surfaces are subject to structural and thermal cracking, and may also cause joint, ligament and tendon damage to players. Hard court surfaces also cause excessive wear to shoes and tennis balls, and cause a tennis ball bounce pattern that is too high and not spin receptive enough to reward a good tennis shot.
Attempts have been made to produce a court surface that would combine the positive attributes of these surfaces while eliminating the disadvantages. Some limited success has been achieved indoors; however all attempts to produce an outdoor surface with the aforementioned desirable characteristics have met with failure.
For example, attempts have been made to laminate closed cell urethane as well as polyethylene foams to a variety of surfaces and in some cases to coat these with acrylic coatings. However, normal seasonal, daily and hourly temperature changes cause undue tension on seams and multiple wrinkles from contraction and expansion of the cells. In addition, most urethanes suitable to such approaches are not suitable for long term outdoor exposure.
Vinyl products with closed cells as well as some open cells have been tried. However, in addition to the same problems with closed cells, unsightly and problematic seams could not be hidden. In addition, surface tack and premature early soiling has been observed. Gradual shrinking as well as surface hardening from gradual plasticizer loss from evaporation as well as water extraction also created problems. Attempts to coat vinyl surfaces with standard color coating systems used in the trade failed for reason of polar affinity of the coatings used with the plasticizers in the vinyl systems. The resulting lowering of the glass transition point of the acrylic, ethylene vinyl acetates, as well as styrene containing copolymers used in the trade created conditions ranging from instant tack to slow gradual softening of the polymer system used.
Furthermore, the prior art consists of assembling components with little or no background or regard for the interaction of the ball to the surface to create a specific type of play.